List reactions and reads

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations indicate readOnlyHint=true, and description adds significant context: always returns complete actor lists, uses two WS calls (UserReactions + UserReads/Mode:1), and is more expensive. No contradictions, full transparency.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Description is a single paragraph with no wasted words; each sentence adds value (purpose, differentiation, cost). Front-loaded with intent. Clear and efficient.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given 4 parameters, read-only annotation, and no output schema, description covers purpose, distinction from siblings, and behavioral details (complete list, two calls). Could briefly mention return structure, but overall adequately complete for agent use.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so baseline is 3. Description does not add parameter-level details beyond schema; mentions output behavior (actors_complete:true) but not parameters. No extra semantic value.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states the tool lists reactions and reads for a message, with specific verb+resource. It explicitly distinguishes from siblings like get_history/get_message_context/get_thread by noting completeness, earning a 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly tells when to use this tool (for complete list) versus alternatives (which may truncate). It also notes higher cost (two WS calls), providing clear usage guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.